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Linux KernelOperating system · Linux

CVE-2026-53027

MEDIUM · 5.5 CVSS v3.1 Published 2026-06-24
Fix available
A fix is available. Upgrade to 6.2 / 7.0.10 or later.
See remediation →
57/100
Remediation priority · Elevated
Zero-click Patch available 8 weeks old

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: fix missing run load for vcn0 in attr_data_get_block_locked() When a compressed or sparse attribute has its clusters frame-aligned, vcn is rounded down to the frame start using cmask, which can result in vcn != vcn0. In this case, vcn and vcn0 may reside in different attribute segments. The code already handles the case where vcn is in a different segment by loading its runs before allocation. However, it fails to load runs for vcn0 when vcn0 resides in a different segment than vcn. This causes run_lookup_entry() to return SPARSE_LCN for vcn0 since its segment was never loaded into the in-memory run list, triggering the WARN_ON(1). Fix this by adding a missing check for vcn0 after the existing vcn segment check. If vcn0 falls outside the current segment range [svcn, evcn1), find and load the attribute segment containing vcn0 before performing the run lookup. The following scenario triggers the bug: attr_data_get_block_locked() vcn = vcn0 & cmask <- vcn != vcn0 after frame alignment load runs for vcn segment <- vcn0 segment not loaded! attr_allocate_clusters() <- allocation succeeds run_lookup_entry(vcn0) <- vcn0 not in run -> SPARSE_LCN WARN_ON(1) <- bug fires here!

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

A race condition in the Linux kernel's NTFS3 filesystem driver causes a missing run load for vcn0 when compressed or sparse attributes have frame-aligned clusters. When vcn is rounded down to the frame start using cmask, vcn != vcn0 and they may reside in different attribute segments. The code loads runs for the vcn segment but fails to load runs for vcn0 when it's in a different segment, causing run_lookup_entry() to return SPARSE_LCN for vcn0 and triggering a WARN_ON(1) kernel bug.

MitigationApply the kernel patch to add the missing check for vcn0 segment loading after the existing vcn segment check in attr_data_get_block_locked(). This is a kernel-level fix requiring kernel source code modification and recompilation.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Linux KernelOperating system
Affected:>= 6.1.132, < 6.2>= 6.2, < 7.0.10

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check kernel version against affected ranges
    Run 'uname -r' or 'cat /proc/version' to get the kernel version. Compare it to the affected ranges: >= 6.1.132 and < 6.2, OR >= 6.2 and < 7.0.10
    Affected if Kernel version falls within either of the two affected ranges
  2. Verify NTFS3 driver is loaded
    Run 'lsmod | grep ntfs3' to check if the ntfs3 kernel module is loaded, or check /proc/filesystems for ntfs3 support
    Affected if NTFS3 driver is loaded or available in the kernel
  3. Check for mounted NTFS3 volumes
    Run 'mount | grep ntfs3' or 'mount -t ntfs3' to see if any NTFS3 partitions are currently mounted
    Affected if Any NTFS3 filesystems are mounted and in use
  4. Inspect kernel logs for the specific crash
    Run 'dmesg' or check /var/log/kern.log for messages containing 'WARN_ON' and 'ntfs3' or 'attr_data_get_block_locked', or look for 'SPARSE_LCN' in kernel logs
    Affected if Kernel logs show the WARN_ON(1) crash related to NTFS3 attribute handling with sparse or compressed files

User is affected if running a kernel version in the affected ranges AND using NTFS3 with compressed or sparse files, as evidenced by the characteristic WARN_ON crash in kernel logs.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 6.2 / 7.0.10 or later
Fixed in 6.27.0.10
Vendor patch git.kernel.org →
Interim mitigation

Apply the kernel patch to add the missing check for vcn0 segment loading after the existing vcn segment check in attr_data_get_block_locked(). This is a kernel-level fix requiring kernel source code modification and recompilation.

Recommended fix High confidence

Linux kernel 7.0.10 or later (or 6.2+ for the 6.1.x branch)

  1. 1. Identify the current running Linux kernel version using 'uname -r'
  2. 2. Check if the running kernel version is affected: any version >= 6.1.132 and < 6.2, or any version >= 6.2 and < 7.0.10
  3. 3. If affected, plan for a system reboot after upgrading the kernel
  4. 4. Upgrade the Linux kernel to version 7.0.10 or later (or to version 6.2 if upgrading from the 6.1.x branch)
  5. 5. After rebooting, verify the fix is applied by checking the kernel version with 'uname -r' and confirming the NTFS3 driver no longer triggers the WARN_ON(1) crash
Caveat Kernel upgrades may require rebooting production systems and could introduce regressions in other drivers or features; ensure compatibility testing in non-production environments first

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Linux Kernel Scoped from the published advisory
  • Consultation4.0 h
  • Implementation6.0 h
  • Testing12.0 h
  • Review / QA4.0 h
26.0 hours of engineering $4,400
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-53027 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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